MIT/GNU Scheme is an implementation of the Scheme programming language, providing an interpreter, compiler, source-code debugger, integrated Emacs-like editor, and a large runtime library. MIT/GNU Scheme is best suited to programming large applications with a rapid development cycle. Recent versions of the system are supported on the following platforms: GNU/Linux, *BSD, OS/2, and Windows.
Petite Chez Scheme is a freely distributable interpreted version of Chez Scheme, a high-performance implementation of ANSI Scheme with numerous extensions. Petite Chez Scheme may be used as a run-time environment for compiled Chez Scheme applications or as a stand-alone Scheme system. With the exception that the compiler is not present, Petite Chez Scheme is completely compatible with Chez Scheme.
Bugloo is a source level debugger for the Scheme compiler Bigloo. It aims at helping to debug Bigloo programs compiled into JVM bytecode. It is implemented by means of the JVM Debugging Architecture, a set of standard APIs provided by Sun to make debuggers and profilers. Currently, Bugloo can debug Bigloo programs, Java programs, or a mix of both. It is based on the debugging model used in GDB and provides additional features like debug sessions, traces, memory debugging, programmable breakpoints and embeddable interpreters. It is a command-line debugger. For the sake of simplicity, it includes a graphical user environment for GNU Emacs or XEmacs.
Roadsend PHP produces optimized stand alone applications, libraries, and Web applications from standard PHP source code. The compiler produces native machine code, not PHP byte code, so no interpreter is required. It is a new implementation of the PHP language and runtime environment compatible with Zend PHP. It does not share any code with the original PHP implementation.